JP2022124842A - Transportation system and transportation method - Google Patents

Abstract

To provide a transportation system simplified in adjustment of the height of an article to the position of a guide rail of a rack, and a transportation method.SOLUTION: A rack 80 has: a pair of first rail parts 82 for supporting a protrusion 91 extending in the depth direction; a pair of first gradient parts 83 sloped downward toward a front face of the rack 80; a pair of second rail parts 84 facing the pair of the first rail parts 82; and a pair of second gradient parts 85 sloped upward toward the front face of the rack 80. A transportation robot 10 has: a top plate 130 for loading an article 90; a lifting part 120 for lifting the top plate 130; one or more load sensors 140 provided on the top plate 130; and a control part 100 for controlling the lifting part 120 on the basis of a measuring result.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to transport systems and transport methods.

Patent Literature 1 discloses an apparatus that transports an article on an elevator and transfers it to a rack. The device described in Patent Literature 1 adjusts the height of the platform during transfer to the rack.

Japanese Patent Application Laid-Open No. 2001-341809

The rack may have guide rails installed to support the object. In such a case, there is a problem that it is difficult to adjust the height of the object to the position of the guide rail due to equipment errors.

The present disclosure has been made to solve such problems, and provides a transport system and a transport method that facilitate adjusting the height of an object to the position of a guide rail provided on a rack. for the purpose.

The transport system in the present embodiment is a transport system that stores an object in a rack by a transport robot,
The object has a protruding portion that protrudes outward in the width direction,
The rack is
a pair of first rails extending in the depth direction for supporting the projection;
a pair of first sloped portions extending from ends of the pair of first rail portions and sloped downward toward the front surface of the rack;
a pair of second rail portions provided above the pair of first rail portions and facing the pair of first rail portions;
a pair of second sloped portions extending from ends of the pair of second rail portions and sloped upward toward the front surface of the rack;
with
The transport robot is
a top plate on which the object is placed;
an elevating unit that elevates the top plate;
one or more load sensors provided on the top plate; and control means for controlling the lifting section based on measurement results obtained by each of the one or more load sensors;
Prepare.

A transport method according to the present embodiment is a transport method for storing an object in a rack by a transport robot,
The object has a protruding portion that protrudes outward in the width direction,
The rack is
a pair of first rails extending in the depth direction for supporting the projection;
a pair of first sloped portions extending from ends of the pair of first rail portions and sloped downward toward the front surface of the rack;
a pair of second rail portions provided above the pair of first rail portions and facing the pair of first rail portions;
a pair of second sloped portions extending from ends of the pair of second rail portions and sloped upward toward the front surface of the rack;
with
The transport robot is
a top plate on which the object is placed;
an elevating unit that elevates the top plate;
one or more load sensors provided on the top plate;
with
The conveying method is
a control step of controlling the lifting unit based on the measurement results obtained by each of the one or more load sensors;
including.

According to the present disclosure, it is possible to provide a transportation system and transportation method that facilitate adjusting the height of an object to the position of a guide rail provided on a rack.

1 is a perspective view showing the configuration of a transport robot according to an embodiment; FIG. It is a side view which shows the structure of the conveyance robot concerning embodiment. 3 is a block diagram showing functions of the transport robot according to the embodiment; FIG. FIG. 4 is a schematic plan view showing a state in which an arm is contracted; FIG. 4 is a schematic plan view showing a state in which an arm is extended; FIG. 10 is a schematic plan view showing a state in which the projecting portion is directed upward after extending the arm. 1 is a schematic front view showing the configuration of a rack according to an embodiment; FIG. It is a schematic side view showing the configuration of the rack according to the embodiment. 1 is a perspective view showing the configuration of an object according to an embodiment; FIG. FIG. 4 is a schematic bottom view showing a plurality of grooves of an object; FIG. 10 is a schematic side view showing a state in which an object according to the embodiment is in contact with a pair of second inclined portions; FIG. 4 is a schematic side view showing a state in which an object according to the embodiment is in contact with a pair of first sloped portions; It is a flow chart which illustrates the flow of the transportation method concerning an embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described through embodiments of the invention, but the invention according to the scope of claims is not limited to the following embodiments. Moreover, not all the configurations described in the embodiments are essential as means for solving the problems.

A transport system according to an embodiment will be described below with reference to the drawings. A transport system according to an embodiment is a system in which a transport robot transports an object. A transport robot stores an object in a rack.

The transport system may include a server that controls the autonomous movement of the transport robot, or the transport robot may generate a transport route by itself and move autonomously. A system in which processing is completed within a transport robot that does not include a server can also be included in the transport system according to the embodiment.

FIG. 1 is a perspective view showing a schematic configuration of a transport robot 10 included in a transport system according to an embodiment. FIG. 2 is a side view showing a schematic configuration of the transport robot 10. As shown in FIG. FIG. 3 is a block diagram showing a schematic system configuration of the transport robot 10. As shown in FIG.

The transport robot 10 includes a movable moving unit 110, an elevating unit 120, a top plate 130 for supporting a placed object, load sensors 140a and 140b, an arm 150, a control unit 100, a wireless and a communication unit 160 . The control unit 100 controls the transfer robot 10 including control of the moving unit 110 , the lifting unit 120 and the arm 150 . Hereinafter, the load sensors 140a and 140b may be referred to as the load sensor 140 when not distinguished from each other. The number of load sensors 140 need not be two, and may be one.

The moving unit 110 includes a robot main body 111, a pair of left and right driving wheels 112 and a pair of front and rear driven wheels 113, which are rotatably provided on the robot main body, and a pair of motors 114 that rotationally drive the driving wheels 112. ing. Each motor 114 rotates each drive wheel 112 via a reduction gear or the like. Each motor 114 rotates each driving wheel 112 according to a control signal from the control unit 100, thereby enabling the robot body 111 to move forward, backward, and rotate. Thereby, the robot body 111 can move to any position. Note that the configuration of the moving unit 110 is merely an example, and is not limited to this. For example, the number of drive wheels 112 and driven wheels 113 of the moving unit 110 may be arbitrary, and any configuration is applicable as long as the robot body 111 can be moved to any position.

The elevating unit 120 is an elastic mechanism that expands and contracts in the vertical direction. The raising/lowering part 120 is also called an expansion/contraction part. The lifting unit 120 may be configured as a telescopic extension mechanism. A top plate 130 is provided at the upper end portion of the lifting section 120 , and the top plate 130 is raised or lowered by the operation of the lifting section 120 . The elevating unit 120 includes a first driving device 121 such as a motor, and expands and contracts by being driven by the first driving device 121 . That is, the driving of the first driving device 121 raises or lowers the top plate 130 . The first driving device 121 drives according to a control signal from the control section 100 . Incidentally, in the transfer robot 10, any known mechanism for controlling the height of the top plate 130 provided on the upper side of the robot main body 111 may be used instead of the elevating section 120. FIG.

The top plate 130 is provided on the top (tip) of the lifting section 120 . The top plate 130 is moved up and down by a driving device such as a motor. For transport, the transport robot 10 moves together with the object while the top plate 130 supports the object. Thereby, the transport robot 10 transports the object.

The top plate 130 is composed of, for example, an upper member 131 and a lower member 132 . The lower member 132 is attached to the upper end of the lifting section 120 . The upper member 131 has a placement surface on which an object is placed.

Moreover, the top plate 130 may have a space for accommodating an arm 150, which will be described later. An arm 150, which will be described later, may be housed inside the upper member 131, for example. The shape of the top plate 130 is, for example, a flat disc shape, but may be any other shape. For example, a notch may be provided in the top plate 130 so as not to interfere with the arm 150 .

The load sensors 140a and 140b are provided, for example, between the upper member 131 and the lower member 132, and measure the load at the provided positions. For example, the load sensor 140 a may be provided on the front side of the top plate 130 and the load sensor 140 b may be provided on the rear side of the top plate 130 . At this time, the load sensor 140 a measures the load applied to the front side of the top plate 130 , and the load sensor 140 b measures the load applied to the rear side of the top plate 130 . Here, the front side and the rear side are the front side and the rear side in the direction in which the object is stored. Therefore, it can be said that the front side of the top plate 130 is the rack 80 side described later. Also, the front side of the top plate 130 can be said to be the side on which an arm 150 described later extends. Each of load sensors 140a and 140b may be, for example, a load cell.

The position where the load sensors 140 a and 140 b are arranged is not limited to between the upper member 131 and the lower member 132 . For example, thin load sensors 140 a and 140 b may be arranged on the mounting surface of the top plate 130 .

Further, the transport robot 10 does not need to have both of the load sensors 140a and 140b, and may have only one of them. Moreover, the position where the load sensor 140 is provided is arbitrary, and is not limited to the front side or the rear side of the top plate 130 described above.

A horizontally extendable arm 150 is provided on the top plate 130 . The arm 150 is an arm for taking an object in and out of a rack 80 which will be described later. The arm 150 has a shaft portion 151 that can extend and contract along an axis and a projection portion 152 . Protrusions 152 extend in a different direction than stem 151 and engage grooves formed in the bottom surface of the object. The projecting portion 152 may extend in a direction perpendicular to the shaft portion 151 at the tip of the shaft portion 151 . That is, arm 150 may have an L-shape. The shape of the tip of the arm 150 is not limited to the hook shape, and may be a shape that holds an object.

The arm 150 includes a second driving device 153 for extending and retracting the arm 150 in the horizontal direction (that is, the direction along the shaft portion 151, in other words, the longitudinal direction of the arm 150). The second driving device 153 may further have a function of rotating the arm 150 with the shaft portion 151 as the rotation axis. The second driving device 153 may be provided inside the upper member 131 of the top plate 130, for example. The second driving device 153 includes, for example, a motor and a linear guide, and extends and contracts the arm 150 in the horizontal direction. The expansion and contraction mechanism is not limited to a structure using a linear guide, and any known mechanism may be used.

4 to 6 show the expansion and contraction of the arm 150. FIG. FIG. 4 is a schematic plan view showing a state in which the transport robot 10 retracts the arm 150. As shown in FIG. FIG. 5 is a schematic plan view showing a state in which the transport robot 10 extends the arm 150. As shown in FIG. FIG. 6 is a schematic plan view showing a state in which the transport robot 10 extends the arm 150 and the protruding portion 152 faces upward.

The wireless communication unit 160 is a circuit for wireless communication in order to communicate with a server or other robots as necessary, and includes, for example, a wireless transmission/reception circuit and an antenna. Note that the wireless communication unit 160 may be omitted when the transport robot 10 does not communicate with other devices.

The control unit 100 is a device that controls the transport robot 10 and includes a processor 1001 , a memory 1002 and an interface (IF) 1003 . The processor 1001, memory 1002, and interface 1003 are interconnected via a data bus or the like.

The interface 1003 is an input/output circuit used to communicate with other devices such as the moving unit 110, the lifting unit 120, the arm 150, the wireless communication unit 160, and the like.

The memory 1002 is configured by, for example, a combination of volatile memory and non-volatile memory. The memory is used to store software (computer program) including one or more instructions executed by the processor, data used for various processes of the transfer robot, and the like.

The processor 1001 may be, for example, a microprocessor, an MPU (Micro Processor Unit), or a CPU (Central Processing Unit). Processor 1001 may include multiple processors. Thus, the control unit 100 is a device that functions as a computer.

The program described above can be stored and supplied to a computer using various types of non-transitory computer readable media. Non-transitory computer-readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (eg, flexible discs, magnetic tapes, hard disk drives), magneto-optical recording media (eg, magneto-optical discs), CD-ROM (Read Only Memory) CD-R, CD - R/W, including semiconductor memory (eg Mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), Flash ROM, RAM (Random Access Memory)). The program may also be supplied to the computer on various types of transitory computer readable medium. Examples of transitory computer-readable media include electrical signals, optical signals, and electromagnetic waves. Transitory computer-readable media can deliver the program to the computer via wired channels, such as wires and optical fibers, or wireless channels.

Next, processing of the control unit 100 will be described. By transmitting a control signal to each motor 114 of the moving part 110, the control part 100 can control the rotation of each drive wheel 112 and move the robot main body 111 to an arbitrary position.

Note that the control unit 100 performs well-known controls such as feedback control and robust control based on rotation information of the driving wheels 112 detected by rotation sensors provided on the driving wheels 112, so that the transport robot 10 You can control movement. Further, the control unit 100 controls the moving unit 110 based on distance information detected by a distance sensor such as a camera or an ultrasonic sensor provided in the transport robot 10 and map information of the moving environment, thereby controlling the transport robot. 10 may be moved autonomously.

Further, the control unit 100 can control the horizontal expansion and contraction of the arm 150 and the direction of the protrusion 152 by transmitting a control signal to the second driving device 153 .

The control unit 100 can control the height of the table top 130 by transmitting a control signal to the first driving device 121 of the lifting unit 120 . Here, the control unit 100 acquires the measurement results from the load sensors 140a and 140b, and controls the height of the table top 130 (that is, the length of the lifting unit 120) based on the measurement results. The details of the method for adjusting the height of the top plate 130 will be described later.

Next, a rack included in the transport system according to the embodiment and an object to be transported will be described. 7 and 8 are a schematic front view and a schematic side view showing the rack 80 and the object 90 housed in the rack 80. FIG. 9 is a perspective view showing the front, bottom and side surfaces of the object 90. FIG.

The object 90 has a protrusion 91 that protrudes in the width direction. Protrusion 91 may be a collar of object 90 . The protrusions 91 are provided on both sides of the object 90 from the front to the back. In the example shown in FIG. 9, the protruding part 91 is provided on the upper part of the object 90, but it may not be provided on the lower part, for example, and may not necessarily be on the upper part.

The housing 81 of the rack 80 has, for example, a top plate, a right side plate, a left side plate, a bottom plate, and a rear plate. The rack 80 has a pair of first rail portions 82 for supporting the projecting portion 91 of the object 90 . The pair of first rail portions 82 extends in the depth direction of the rack 80 . The pair of first rail portions 82 are provided in parallel at the same height. Although four pairs of first rail portions 82 are provided in FIGS. 7 and 8, the number of pairs of first rail portions 82 is arbitrary. The object 90 is supported by one of the pair of first rail portions 82 on one of the protruding portions 91 and by the other of the pair of first rail portions 82 on the other of the protruding portions 91 . The pair of first rail portions 82 are provided from the front to the back of the rack 80 . The rack 80 also includes a pair of first sloped portions 83 extending from the ends of the pair of first rail portions 82 . The pair of first sloped portions 83 slope downward toward the front surface of the rack 80 .

The rack 80 has a pair of second rail portions 84 above the pair of first rail portions 82 . The pair of second rail portions 84 faces the pair of first rail portions 82 . The object 90 is accommodated so that the projecting portion 91 is positioned between the pair of first rail portions 82 and the pair of second rail portions 84 . A locking mechanism for locking the stored object 90 may be attached to the pair of second rail portions 84 . The rack 80 also includes a pair of second sloped portions 85 extending from the ends of the pair of second rail portions 84 . The pair of second sloped portions 85 slope upward toward the front surface of the rack 80 . The pair of first rail portions 82 , the pair of first sloped portions 83 , the pair of second rail portions 84 , and the pair of second sloped portions 85 constitute a guide rail structure of the rack 80 .

The rack 80 supports projecting portions 91 provided on both sides of the object 90 from below by a pair of first rail portions 82 . The object 90 can move forward and backward within the rack 80 along the pair of first rail portions 82 . That is, the object 90 can be pulled out from the rack 80 by pulling the object 90 toward the front of the rack 80 .

As shown in FIG. 9, the bottom surface of the object 90 may have a groove 92 formed at a predetermined position for hooking the protrusion 152 of the arm 150 . The groove 92 may have, for example, a semi-cylindrical shape whose axial direction is the direction in which the object 90 is pulled out. If the tip of the arm 150 has a shape that sandwiches the object 90 , the object 90 may not have the groove 92 .

The control unit 100 of the transfer robot 10 operates the arm 150 to move the object 90 from the rack 80 to the top plate 130 or move the object 90 from the top plate 130 to the rack 80 . A method for the transport robot 10 to pull out the object 90 from the rack 80 will be described below.

The controller 100 , for example, extends the arm 150 by a predetermined length and moves the protrusion 152 of the arm 150 into the groove 92 on the bottom surface of the object 90 . Here, the protrusion 152 may be oriented horizontally. Then, the control unit 100 rotates the protrusion 152 with the shaft 151 of the arm 150 as a rotation axis to enter the groove 92 of the object 90 . The control unit 100 may extend the arm 150 with the protrusion 152 facing upward, and then lift the top plate 130 to insert the protrusion 152 into the groove 92 .

Then, the transport robot 10 retracts the arm 150 while the protrusion 152 of the arm 150 is caught in the groove 92 . Thereby, the object 90 is pulled out from the rack 80 and moved to the top plate 130 . On the other hand, the control unit 100 extends the arm 150 with the protrusion 152 in the groove 92 and pushes the object 90 into the rack 80 , thereby storing the object 90 on the top plate 130 in the rack 80 . be able to.

By the way, the number of grooves 92 of the object 90 may be one as shown in FIG. 9, or may be plural as shown in FIG. FIG. 10 is a schematic bottom view of the object 90. FIG. Specifically, it has a plurality of grooves 92 aligned in the vertical direction, that is, the direction of movement of the object 90 . In this case, when moving the object 90 accommodated in the rack 80 to the top plate 130 , the control unit 100 of the transfer robot 10 hooks the tip of the arm 150 in order from the groove 92 on the top plate 130 side to move the object 90 from the rack 80 . may be repeated. Similarly, when moving the object 90 on the top plate 130 to the rack 80 , the controller 100 of the transfer robot 10 hooks the tip of the arm 150 in order from the groove on the rack 80 side, thereby pushing the object 90 into the rack 80 . You can repeat.

Next, a method for controlling the lifting section 120 by the control section 100 of the transport robot 10 based on the measurement results of the load sensors 140a and 140b will be described. Assume that the transport robot 10 is moving to the front of the rack 80 with the object 90 placed on the top plate 130 . The transport robot 10 first raises the top plate 130 to a target height. The target height may be set between the height of the upper ends of the pair of first rail portions 82 and the height of the lower ends of the pair of second rail portions 84 .

Next, the transport robot 10 extends the arm 150 while the protrusion 152 is caught by the object 90 on the top plate 130 . Here, when the top plate 130 is controlled to have the height described above, the transport robot 10 can store the object 90 in the rack 80 by extending the arm 150 . On the other hand, when the height of the top plate 130 is higher than the target height, the object 90 may come into contact with the pair of second sloped portions 85 . Also, if the height of the top plate 130 is lower than the target height, the object 90 may come into contact with the first slope portion 83 . In such a case, the transport robot 10 controls the elevation unit 120 based on the measurement results of the load sensors 140a and 140b to adjust the height of the top plate 130. FIG.

A method for controlling the height of the top plate 130 will be described with reference to FIGS. 11 and 12. FIG. FIG. 11 is a schematic side view showing a state in which the object 90 is in contact with the pair of second inclined portions 85. As shown in FIG. In such a case, the object 90 tilts downward toward the rack 80 side. Therefore, the load measured by load sensor 140a increases and the load measured by load sensor 140b decreases.

On the other hand, FIG. 12 is a schematic side view showing a state in which the object 90 is in contact with the pair of first sloped portions 83. As shown in FIG. In such a case, the object 90 tilts upward toward the rack 80 side. Therefore, the load measured by load sensor 140a decreases and the load measured by load sensor 140b increases.

When the height of the top plate 130 is lowered from the state of FIG. 11, the inclination of the object 90 becomes smaller. changes. Then, when the protruding portion 91 of the object 90 stops contacting the pair of second inclined portions 85, the inclination of the object 90 becomes zero.

When the height of the top plate 130 is further lowered, the projecting portion 91 of the object 90 comes into contact with the pair of first inclined portions 83 . Then, as shown in FIG. 12, object 90 begins to tilt in the direction opposite to that in FIG. As the height of the top plate 130 is further lowered, the inclination of the object 90 increases, and the measurement result of the load sensor 140a and the measurement result of the load sensor 140b change according to the inclination of the object 90. .

That is, when the height of the tabletop 130 is changed from the state shown in FIG. 11 or the state shown in FIG. 12, the tilt angle of the object 90 changes. As the inclination angle of the object 90 changes, the measurement result of the load sensor 140a and the measurement result of the load sensor 140b change. Therefore, the control unit 100 of the transport robot 10 can feedback-control the height of the tabletop 130 based on the measurement results of the load sensors 140a and 140b.

The control unit 100 can feedback-control the lifting unit 120 based on the difference between the measurement results of the two load sensors 140a and 140b. For example, control unit 100 calculates the difference between the load measured by load sensor 140a and the load measured by load sensor 140b, and feedback-controls the height of top plate 130 so that the difference becomes zero. good too. The control unit 100 can also perform feedback control so that the load measured by either the load sensor 140a or the load sensor 140b becomes the target value. Therefore, as described above, the transport robot 10 only needs to include one of the load sensors 140a and 140b.

FIG. 13 is a flow chart showing the flow of the transport method according to the embodiment. It is assumed that the transport robot 10 places an object 90 on the top plate 130 and stops in front of the rack 80 . First, the control unit 100 performs feedforward control by controlling the lifting unit 120 so that the height of the tabletop 130 becomes a target value (step S101). Here, the control unit 100 may not be able to control the height of the top board 130 between the height of the pair of first rail portions 82 and the height between the pair of second rail portions 84 due to equipment error or the like. have a nature.

Next, the controller 100 of the transfer robot 10 pushes the object 90 engaged with the tip of the arm 150 into the rack 80 (step S102). Next, the controller 100 of the transport robot 10 determines whether or not the object 90 has been successfully stored (step S103). For example, the controller 100 of the transport robot 10 may determine whether the object 90 has been stored in the rack 80 based on the detection results of the load sensor 140 or other sensors. Further, the control unit 100 may determine whether or not the object 90 could be stored in the rack 80 based on the length of the extended arm 150 .

If the object 90 can be stored in the rack 80 (Yes in step S103), the control unit 100 ends the process. On the other hand, if the object 90 could not be stored in the rack 80 (No in step S103), the control unit 100 controls the lifting unit 120 based on the measurement results of the load sensors 140a and 140b to The height of the plate 130 is feedback-controlled (step S105). In the case of FIG. 11, the control unit 100 lowers the tabletop 130 according to the measurement results of the load sensors 140a and 140b. In the case of FIG. 12, the control unit 100 raises the top board 130 according to the measurement results of the load sensors 140a and 140b.

After controlling the height of the top plate 130, the control unit 100 further extends the arm 150 and pushes the object 90 into the rack (step S106). If the object 90 could not be stored in the rack 80 in step S106, the controller 100 may perform feedback control in step S105 again.

Finally, the effects of the transport system according to the embodiment will be described in detail. When storing an object in a rack with guide rails, it was sometimes difficult to control the height only by feedforward control. The transport robot according to the embodiment can control the height of the top board according to the inclination of the object when the object comes into contact with the first sloped portion and the second sloped portion. Therefore, the transport system according to the embodiment can facilitate adjusting the height of the object to the position of the guide rail.

It should be noted that the present invention is not limited to the above embodiments, and can be modified as appropriate without departing from the scope of the invention.

10 Transfer Robot 100 Control Unit 1001 Processor 1002 Memory 1003 Interface 101 Drive Control Unit 102 Detection Unit 110 Moving Unit 111 Robot Main Body 112 Drive Wheel 113 Driven Wheel 114 Motor 120 Lifting Unit 121 First Drive Device 130 Top Board 131 Upper Member 132 Lower Member 140, 140a, 140b load sensor 150 arm 151 shaft 152 projection 153 second driving device 160 wireless communication section 80 rack 81 housing 82 first rail section 83 first slope section 84 second rail section 85 second slope section 90 Object 91 Projection 92 Groove

Claims (6)

A transport system for storing an object in a rack by a transport robot,
The object has a protruding portion that protrudes outward in the width direction,
The rack is
a pair of first rails extending in the depth direction for supporting the projection;
a pair of first sloped portions extending from ends of the pair of first rail portions and sloped downward toward the front surface of the rack;
a pair of second rail portions provided above the pair of first rail portions and facing the pair of first rail portions;
a pair of second sloped portions extending from ends of the pair of second rail portions and sloped upward toward the front surface of the rack;
with
The transport robot is
a top plate on which the object is placed;
an elevating unit that elevates the top plate;
one or more load sensors provided on the top plate; and control means for controlling the lifting section based on measurement results obtained by each of the one or more load sensors;
comprising
transport system. The transport robot is
Two load sensors are provided as the one or more load sensors,
One of the two load sensors is provided on the front side of the top plate, and the other of the two load sensors is provided on the rear side of the top plate,
The control means is
controlling the lifting unit based on the difference between the measurement results of the two load sensors;
A transport system according to claim 1 . each of the one or more load sensors is a load cell;
3. A transport system according to claim 1 or 2. The transport robot is
an arm provided on the top plate for taking the object in and out of the rack;
further comprising
The control means is
After controlling the lifting unit by feedforward control, the object is pushed into the rack using the arm;
If the object cannot be stored in the rack, feedback control of the lifting unit is performed based on the measurement results obtained by each of the one or more load sensors.
The transport system according to any one of claims 1 to 3. A transport method for storing an object in a rack by a transport robot,
The object has a protruding portion that protrudes outward in the width direction,
The rack is
a pair of first rails extending in the depth direction for supporting the projection;
a pair of first sloped portions extending from ends of the pair of first rail portions and sloped downward toward the front surface of the rack;
a pair of second rail portions provided above the pair of first rail portions and facing the pair of first rail portions;
a pair of second sloped portions extending from ends of the pair of second rail portions and sloped upward toward the front surface of the rack;
with
The transport robot is
a top plate on which the object is placed;
an elevating unit that elevates the top plate;
one or more load sensors provided on the top plate;
with
The conveying method is
a control step of controlling the lifting unit based on the measurement results obtained by each of the one or more load sensors;
method of transportation, including; The transport robot is
Two load sensors are provided as the one or more load sensors,
One of the two load sensors is provided on the front side of the top plate, and the other of the two load sensors is provided on the rear side of the top plate,
The control step includes:
controlling the lifting unit based on the difference between the detection results of the two load sensors;
The conveying method according to claim 5.

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